Pressurized liquid extraction of bioactive compounds from grape peel and application in pH-sensing carboxymethyl cellulose films: A promising material to monitor the freshness of pork and milk.

This study produced pH-sensing carboxymethyl cellulose (CMC) films functionalized with bioactive compounds obtained by pressurized liquid extraction (PLE) of grape peel to monitor the freshness of pork and milk. A semi-continuous PLE was conducted using hydroethanolic solution (70:30, v/v) at a flow rate of 5 mL/min, 15 MPa, and 60 °C. The films were produced by the casting technique using CMC (2.5 %, w/v), glycerol (1 %, v/v), and functionalized with 10, 30, and 50 % (v/v) grape peel extract. From the results obtained, LC-MS/MS revealed that PLE extracted twenty-seven phenolic compounds. The main phenolic compounds were kaempferol-3-glucoside (367.23 ± 25.88 µg/mL), prunin (270.23 ± 3.62 µg/mL), p-coumaric acid (236.43 ± 26.02 µg/mL), and procyanidin B1 (117.17 ± 7.29 µg/mL). The CMC films presented suitable color and mechanical properties for food packaging applications. The addition of grape peel extract promoted the pH-sensing property, showing the sensitivity of anthocyanins to pH changes. The films functionalized with grape peel extract presented good release control of bioactive compounds, making them suitable for food packaging applications. When applied to monitor the freshness of pork and milk, the films exhibited remarkable color changes associated with the pH of the food during storage. In conclusion, PLE is a sustainable approach to obtaining bioactive compounds from the grape peel, which can be applied in the formulation of pH-sensing films as a promising sustainable material to monitor food freshness during storage.

Application of nanoparticles entrapped orange essential oil to inhibit the incidence of phytopathogenic fungi during storage of agroecological maize seeds.

The demand for sustainable, healthy, and pesticide-free food has grown in recent years. Agroecological seeds cannot receive chemical treatment, as pesticides present toxicological and environmental risks, requiring the development of alternative methods for disease control, such as the use of essential oils. In this study, orange essential oil was extracted and encapsulated in zein nanoparticles by the nanoprecipitation method. The nanoparticles were tested for the antifungal activity on agroecological maize seeds and for the mycelial sensitivity of Stenocarpella macrospora. The synthesized nanoparticles presented good encapsulation efficiency (99 %) of orange essential oil rich in D-limonene, conferring high antioxidant activity to the loaded nanoparticles. The release profile indicated a pseudo-Fickian mechanism governed by diffusion, explained according to the Korsmeyer-Peppas model. The dynamic light scattering, and transmission electron microscopy showed spherical nanoparticles with particle size lower than 200 nm. The nanoparticles containing orange essential oil inhibited the incidence of Fusarium during the storage of agroecological maize seeds. The mycelial sensitivity against Stenocarpella macrospora showed that the encapsulated essential oil was more effective in inhibiting the fungus when compared to the non-encapsulated oil. Therefore, the nanoparticles containing encapsulated orange essential oil can be effectively applied as an antifungal material for the conservation of agroecological maize seeds, contributing to the development of sustainable agricultural biotechnology with pesticide-free products.

Production of methylcellulose films functionalized with poly-ε-caprolactone nanocapsules entrapped ß-carotene for food packaging application.

Nowadays, there is a worldwide demand in the production of innovative packaging that release active compounds to increase the shelf life of perishable food products. Therefore, this study produced methylcellulose films functionalized with poly-ε-caprolactone nanocapsules entrapped ß-carotene. The nanoparticles were produced by the nanoprecipitation method, and 10, 30, and 50 % of nanoparticles colloidal solution was added in the methylcellulose filmogenic solution. The films were characterized by the mechanical, physicochemical properties, antioxidant activity, and release of ß-carotene from the polymeric matrix to a food simulant. The results demonstrated satisfactory mechanical properties; however, the addition of nanoparticles decreased the Young's Modulus and increased the elongation at break. Regarding light transmission, the incorporation of ß-carotene nanoparticles promoted a decrease in the percentage of ultraviolet ray's transmittance through the film matrix, as well as visible light. The incorporation of nanoparticles improved the antioxidant activity of the films, which was proportional to the concentration of ß-carotene used in the formulation. The release of ß-carotene reached a maximum value of 10.93 µg g-1 film containing 70 % nanoparticles, which was a desired profile for food application. Finally, the methylcellulose films functionalized with poly-ε-caprolactone nanocapsules can release ß-carotene, and therefore, can be considered as a novel nanomaterial for food conservation, with a potential to increase the shelf life of perishable food products.

Application in situ of biodegradable films produced with starch, citric pectin and functionalized with feijoa (Acca sellowiana (Berg) Burret) extracts: An effective proposal for food conservation.

In this study, biodegradable films produced with starch, citric pectin, and functionalized with antioxidant compounds from feijoa (Acca sellowiana (Berg) Burret) were in situ applied for the conservation of ground beef, bread, and grapes. The results demonstrated that the films produced were an excellent source of stable antioxidant compounds, with antimicrobial activity against Escherichia coli, Salmonella, and Shigella. The bioactive films based on biological macromolecules positively stabilized the polyunsaturated fatty acids and deterioration reactions in ground beef. The release of bioactive compounds from the films was responsible for inhibiting molds and yeasts in bread, increasing their shelf life for 30 days of storage. The application of film coating and packaging in grapes increased postharvest conservation and maintained steady physicochemical characteristics. Therefore, the innovative films produced can release bioactive compounds with antioxidant and antimicrobial activity, and consequently, can be proposed as an effective material for food conservation, increasing the shelf life of perishable food products.

Chitosan packaging functionalized with Cinnamodendron dinisii essential oil loaded zein: A proposal for meat conservation.

The nanoencapsulation of essential oils for biodegradable films functionalization is a viable alternative for the production of active food packaging. In this study, the Cinnamodendron dinisii Schwanke essential oil was nanoencapsulated using zein as wall material, and applied in chitosan matrix to produce an active nanocomposite film packaging for food conservation. The chemical composition of the Cinnamodendron dinisii Schwanke essential oil showed a variety of unexplored bioactive compounds, and 1,8-cineole was the major compound. The oil nanoencapsulation produced stable and homogeneous nanoparticles with zeta potential close to 30 mV and polydispersity index lower than 0.2. The nanoparticles size showed a size variation between 70 and 110 nm. The chitosan films obtained functionalized with nanoparticles demonstrated antioxidant activity and antimicrobial activity. The active packaging containing zein nanoparticles was efficient in the conservation of ground beef, stabilizing the deterioration reactions and preserving the color.

Feijoa [Acca sellowiana (Berg) Burret] accessions characterization and discrimination by chemometrics.

BACKGROUND: Feijoa [Acca sellowiana (Berg) Burret] is a Brazilian native fruit with few commercial-level plantations and high agroindustrial potential. A genotype evaluation experiment was conducted from 1996 onward, aiming to obtain fruits based on the agronomical parameters; however, the selection based on chemical composition had not been evaluated with respect to developing a new cultivar. Accordingly, the present study aimed to discriminate seven accessions of feijoa in terms of nutritional composition, phenolic compounds and antioxidant activity using multivariate analysis (principal component analysis and multivariate contrast), targeting the potential production of a new cultivar with better nutritional value and high antioxidant capacity. RESULTS: Feijoa husk presented high content of ashes, lipids, proteins, carbohydrates, phenolic compounds and antioxidant activity compared to feijoa pulp. However, only feijoa pulp was selected to multivariate analysis because it is the fruit edible part. Data variability was explained in 78% and the feijoa pulp accessions were discriminated into four groups related to their characteristics. The accession 5 discrimination can be explained by the high content of ashes, carbohydrates, soluble solids, phenolic compounds and antioxidant activity. Accession 6 was also discriminated by the high content of total acidity, pH and proteins, as well as a low content of soluble solids. CONCLUSION: Feijoa accessions may be indicated for increasing plant selection via hybridization with the other accessions, aiming to produce new cultivars with better nutritional composition and antioxidant capacity. For example, accession 5 is the most suited fruit for human consumption and is a potential plant with respect to becoming a new cultivar. © 2020 Society of Chemical Industry.

Bioactive food packaging based on starch, citric pectin and functionalized with Acca sellowiana waste by-product: Characterization and application in the postharvest conservation of apple.

Innovative biodegradable packaging with antimicrobial and antioxidant properties was developed, and functionalized with Acca sellowiana waste by-product (feijoa peel flour, FPF). Physicochemical, morphological, antioxidant, antimicrobial properties, and in situ application in the postharvest conservation of apple were conducted with the packaging produced. The results obtained demonstrate that FPF addition had a positive influence on the packaging characteristics, for all the parameters tested. The high concentration of antioxidant compounds in the films with FPF promoted antimicrobial activity against Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa. The packaging produced maintained the quality of apples during storage, with constant weight after 5 days of storage. Based on our results, the bioactive, antioxidant and antimicrobial packaging functionalized with Acca sellowiana waste by-product may be considered as a new alternative to packaging in food systems.

Antioxidant and antimicrobial methylcellulose films containing Lippia alba extract and silver nanoparticles.

Methylcellulose is a biopolymer, which can be used in the preparation of films for the production of biodegradable active packaging. In this work, the methylcellulose films containing biosynthesized silver nanoparticles (AgNPs) were developed using Lippia alba extract. The physico-chemical, antioxidant, and antimicrobial properties of the films were studied. The insertion of Lippia alba compounds was verified using infrared spectroscopy (FTIR), with the appearance of a band at 1595 cm-1 and 1410 cm-1 which is characteristic of CCC stretches of the aromatic ring, and the increase in the hydrophobicity of the films containing the extract in relation to the control film. The films containing AgNPs presented a decrease in tensile strength and elastic modulus, but increased elongation. It was observed that the films that contain AgNPs presented superior antioxidant activity compared to the other films, besides antimicrobial activity against the tested microorganisms.